In the opening scene, Ray and Abby's car is driving through a horrible rainstorm. When they suddenly stop to allow Loren's VW Beetle to pass, the exterior shots show no rain.
The German shepherd at Ray's house is different from the one at Marty's.
When Abby's revolver is first seen in her purse, it is a detective-style gun with a dark finish and dark handle with an enclosed hammer and no cocking lever. For the rest of the movie, it is a shiny silver ivory grip revolver with a cocking lever.
Bullet holes through the wall in the final scene keep changing.
When Marty is going to arrange the killings, he is wearing a ruby pinkie ring on his right hand. Minutes later, when sitting with Visser in the VW, the ring is a diamond horseshoe.
After Visser empties the magazine of his gun through the wall, he continues to pull the trigger and the gun is heard cycling. This is the sound of a revolver. With a revolver, one can continue to pull the trigger after all the bullets have been expended. His gun was a .45 caliber semi-automatic, and the trigger locks after the last shot.
In addition, when using a semi-automatic, the slide locks back after the last shot has been taken. The slide of his gun is not locked back when it is seen on the floor.
In addition, when using a semi-automatic, the slide locks back after the last shot has been taken. The slide of his gun is not locked back when it is seen on the floor.
Abby's revolver has only three rounds loaded. One is fired when Visser shoots Marty, and the second when Ray accidentally kicks the gun (although this cannot happen, as the hammer is down on a fired round).
However, when Ray is trying to bury Marty, Marty regains consciousness, pulls the revolver out of his pocket and pulls the trigger several times. It should fire the third round, but nothing happens. Then when Abby uses the revolver to shoot Visser, the third round fires. There is no way this series of events can happen. The director may have wanted Marty to pull the trigger of the revolver for dramatic effect, but if he did so, he would have shot Ray.
However, when Ray is trying to bury Marty, Marty regains consciousness, pulls the revolver out of his pocket and pulls the trigger several times. It should fire the third round, but nothing happens. Then when Abby uses the revolver to shoot Visser, the third round fires. There is no way this series of events can happen. The director may have wanted Marty to pull the trigger of the revolver for dramatic effect, but if he did so, he would have shot Ray.
Abby has a .32 Iver Johnson revolver, and a new box of .32 Winchester-Western ammunition (marked blank, as has been noted). But the box only contains three rounds, and these are clearly very old. The brass of the cases and the lead of the bullets are oxidized. They must be decades old, yet are in a brand new box.
A radio station's call letters begin with W. The boundary in the US between radio/TV call letters beginning with W and those beginning with K was not always the Mississippi River. In the 1980s, Texas still had more than one "W" station. In the east, there is KDKA and KQV in Pittsburgh, Pennsylvania for example as well.
The box of shells from which Abby dumps three live rounds is clearly labeled "blanks" and .32 caliber. Abby said earlier that the gun her husband gave her is a .38.
When private detective Loren Visser steals Abby's gun, the supposedly unfired shells have visible depressions in the primers, indicating they already have been fired.
When Visser is sitting at the table in the bar across from Marty (the first time), he lights his cigarette with his lighter, and his hand is shown putting the lighter on the table. The hand looks like that of a younger man, and the huge ring on Visser's right hand is missing in that shot.
Loren discovers his lighter is missing when he goes to light a cigarette after burning the doctored photos. Logically, he would have used his lighter to light the pictures in the first place, so he would have discovered his lighter was missing when he tried to burn them. Also, as a heavy smoker, he likely would have tried to light a cigarette well before he would have gotten to burning the photos.
Phone continues to ring after Abby picks it up.
When the detective is leaving Ray's house at night, you can see someone standing in the shot.
After Marty tries to attack his wife outside Ray's house, he walks across the lawn to his van. For a split second the camera rig comes into shot on the right hand side of the screen.
A reflection of the camera crane is visible in a phone booth.
When Ray is talking to Abby in her apartment and explaining that if you shoot someone, you need to make sure he's dead, the boom shadow is briefly visible on the bathroom door.
As Ray drags unconscious Marty across the furrowed field, the soles of Marty's boots are caked in mud. Marty has not walked on mud, only in his office and on the road, his soles should be clean.
When Abby smashes the window onto Visser's hand the natural reaction would be to pull the hand back immediately in pain.